Hydraulic device for stabilizing and steering purposes



Aug- 12, 1941- n w. KULIKOFF HYDRAULIC DEVICE FOR STABILIZING AND STEERING PURPOSES 2 sheets-sheet 1 Filed Jan. 27, 1959 Y willig/Ill!! lll Illlll Align l2, 1941. W, KULlKOFF l 2,252,660

HYDRAULIC DEVICE FOR STABILIZING AND STEERING PURPOSES Filed Jan. 27, 1959 2 `Sheets-Sheet 2 Patented Aug. l2, 1941 HYDRAULIC DEVIOE FOB STABILIZIN G AND STEERING PURPOSES Waldemar Kullkoil, Berlin-Grunewald, Germany Application January 27, 1939, Serial No. 253,161 In Germany February 5, 1938 1 Claim.

This invention relates to a hydraulic device for stabilizing and steering purposes, for example. for' (Cl. Isn-'192) Such auxiliary power steering devices are pro-- vided with a valve actuated by the steering Wheel. This valve controls the admission of a pressure medium to the operating piston movably arranged in a cylinder forming part of a hydraulic circuit. By way of a steering linkage the pistons act upon the stub axles or swivels of the vehicle.

The known steering devices of this lind have the disadvantage that the steering is mechanically effected by use of more or lesscomplicated devices. The steering devices are extremely sensitive to Wear. The reliability of the lmown hydraulic steering arrangements is, therefore, unsatisfactory.

The present invention relates to a hydraulic auxiliary steering device for motor-cars which is free of all the disadvantages of the known cievices of this kind. Moreover, with regard to the latter the device according to the invention has the advantage that complicated mechanical con trols are unnecessary, that the steering linkage is completely relieved of load and that during drive the wheels to be steeredare locked in the adjusted position'thus preventing that shocks due to obstructions on the roadway are transferred to the steering wheel.

The device according to the invention directiy acts upon the road wheels of the vehicle to be l steered, thereby relieving the steering linkage. The hydraulic operating. system is hydraulically controlled without the assistance of a mechanical control.

In the accompanying drawings the invention is shown by way of example.

In these drawings:

Fig. 1 is a. diagrammatic view of an auxiliary power steering arrangement according to the invention,

Fig. 2 shows a section through one of the operating pistons.

Figs. 3, 4, 5, 6, 7, 8 and 9 show details of some constructions and various operative positions of the control valve.

In the construction of the auxiliary steering arrangement according to the invention shown in Fig. l, the steering Wheel 26 is by way of a. steering gear 28 and a steering arm 21 connected to a piston l reciprocatably arranged in a movable cylinder 2. The latter is rigidly connected to the connecting rod 23 of the steering mechanism. The rod 23 is pivoted to the lever 24 of the stub axle or swivel 25. The lever 24 in turn is rigidly connected to the stub axle or swivel 25 of the motor-car. The upper and lower chambers 29 and 30 respectively of the cylinder 2' are connected to the pressure chambers ofv a control cylinder 3 by means oi pipes 3l and 32 respectively. Movably arranged in the cylinder 3 is a control piston ll which. in turn is pivoted to the control valve 6. The cylinder 2, the pipes 3|, 32 and the cylinder 3 together iorm the primary hydraulic circuit.

The control valve t, for instance the rotary valve, shown in detail in Figs. 3-9 is, as may be seen from l, connected to the operating cyl- -inders di? and by pipes ld and In each oi the cylinders iii and Elfi a piston l5 is movably arranged which is connected to a lever dll. The latter is rigidly connected to a rotatable bolt il which in turn is rigidly connected to the stub axle or swivel 25, the arrangement being such that the stub axle or swivel is adjusted by the movements or" the piston le (see Figs. l and 2). .Il pipe 2l connects 'the control valve i3 to a collecting vessel d which by way oi a pipe it is connected to a feed pump 36. By way of a pipe 3l the pump 35 forces the liquid into the closed vessel The vessel t is open to the atmosphere. By way of a pipe 39 the vessel ti, containing liquid under pressure, is connected to a pressure gauge or manometer The control valve li may close the pipes t9 and 2d or admit the flow o pressure liquid to the operating chambers of the cylinders 33 and 3i.

in Fig. 3 the controi valve, formed as a rotary valve, is shown in a position in which all passages of the valve are closed.

Fig. i illustrates a position o the control valve in which the passages are fully opened so that the pressure liquid, flowing through the pipe i8, may reach the pipe i9 and serve to hydraulically operate the steering.

Fig. 5 also shows the valve with fully opened passages, in this case, however, in a reversed direction as illustrated in Fig. 4. The pressure liquid flows from the pipe i8 into the pipe 2li and in this case also serves to hydraulically operate the steering.

The valves shown in Figs. 6, 7, and 8 correspond to those illustrated in Figs. 3, 4, and 5, respectively, and show the action of a control valve having overflow passages A.

Fig. 6 shows the pipe I8 closed, whereas the vpipes IS, 2l and 20 are connected to each other by the passages a so that the pistons are not Y locked but only checked. The resistance opposed to the movement of the piston is dependent on the larger or smaller cross-section of the passages A. The locking of the wheels in this case, therefore, is not complete so that an elastic steering is warranted. Y

Figs. 7 and 8 show the operating positions which the control valve occupies during the hydraulic operation of the steering.

Fig. 9 illustrates a control valve similar to that shown in Figs. 6, 7 and 8. The passages A, howover, are replaced in this case by slots a provided between the movable member of the control'valve and the return pipe 2I.

'I'he operation oi.' the device according to the I invention is about as follows:

If the steering wheel 26 is turned in the direction of the arrow 42 by the driver of the motorcar, the piston I of the impulse cylinder 2 is moved by the' steering arm 21. The pressure dii'- ferences produced hereby in the control. cylinder 3 move the piston II and thereby the control valve 6 in such a manner that the pipes I8 and 20 are connected to the pipes I9 and 2l respectively. The movement of the individual elements and the direction of ilow of the pressure liquid are indicated in the drawings by arrows. Each of the operating pistons I movably arranged in the operating cylinders will be connected to the vessel 5 containing the liquid under pressure and, therefore, actuate the stub axles or swivels 25 in the desired direction as long as the steering wheel 26 is turned by the driver. Hereby the lever 24 and the rod 23 connected thereto is moved which latter is rigidly connected to the movable impulse cylinder 2. The position of the piston I relatively to the cylinder 2, therefore, is not changed as long as the driver turns the steering wheel. As soon as the steering hand wheel 26 ceases to turn, the piston I remains stationary while its cylinder 2 carries out a small subsequent displacement whereby the piston I will attain its middle position in the cylinder and the twohydraulic circuits will again reach their position o! rest in are locked.

which the wheels to be steered V The device described above and shown in the drawings also serves to absorb any shocks which otherwise would act upon the wheels to be steered and which may be produced in the case ofthe turning o! the vehicle, for example by an obstruction on the roadway or owing to tire troubles, as such shocks will effect movement of the cylinder ,2. The shock thuscannot snatch or wrest the steering wheel out of the driver's hand.

The auxiliary steering mechanism according to the invention may be used with other known types of wheel suspension.

What I claim is:

A hydraulic device for steering the road wheels of road vehicles comprising the subcombination of: a ilrst hydraulic circuit; a movable cylinder; a movable piston in said cylinder; means for moving said piston; and a movable control member, said cylinder, piston and control member being included in said first circuit; a second hydraulic circuit operatively associated with said ilrst circuit; a iiuid supply container; a valve device adapted to control the flow of fluid in said second circuit, said device being operatively connected to said control member in said first circuit and a main operating piston for connection to a stub axle of the vehicle road wheels, said container, valve device and piston being included in said second circuit, the arrangement being such that, on actuation of said piston in said iirst circuit, said control member Is moved positively to actuate said valve device to allow uid in said second circuit to flow in said circuit and actuate said main operating piston in said second circuit; and linl; mechanism positively connecting said last-mentioned piston to said movable cylinder in said rst circuit for the purpose of causing said piston in said cylinder to return to itsy initial neutral position, on said movingvmeans ceasing to operate, and closing said second` circuit subs tantially as described.

WALDEMAR KULIKOFF. 

